Refrigerating mechanism



May 26, 1931. c. c. THOMAS REFRIGERATING MECHANISM Filed Jan. 18, 1928 2 Sheets-Sheet 1 q Rea Y ,Mw .M m7 w 4 A 6 m R m C Y B May 26, 1931. c. c. THOMAS v 1,807,354

REFRIGERATIIfIG' MECHANI SI Filed Jan. 18, 1928 2 Sheets-Sheet 2 ACT! VA TE l/VVENTOR C'H/IHLL'J C. THO/VH5.

- R6 B Y YTORNE y Patented May 26, 1 931- UNITED STATES PATENT. OFFIIICIE CHARLES C. THOMAS, F DETROIT, MIiCHIG-AN, ASSIGIN'OR TO COPELAND PRODUCTS, INC A CORPORATION MICHIGAN REFRIGERATINVGYMEGHANISM Applicationfiled January 18, '1928. Serial No. 247,683.

This invention relates to refrigerating mechanism and particularly. to such mechanism of the absorber or adsorber type, the principal object being the provision of a construction therefor which will enable the same to be operated in a more satisfactoryandv economical manner than has heretofore been possible with the conventional design of this type.

Another object is to provide a refrigerating mechanism of the type described in which cooling is discontinued and heat is applied to-the combined adsorber or absorber and generator, or as it is hereinafter referred to, refrigerant transformer, in accordance with the presence of a predetermined pressure in the evaporator during a rise in pressure therein rom a minimum cycle pressure.

Another object is to provide a device of the type described in which theheatto the refrigerant transformer is discontinued and cooling of the same is begun upon a predetermined drop in pressure within the transformer from a maximum cycle pressure.

A further object is to provide a device of the type described including a refrigerant transformer enclosed in a container, a heating element being positioned within the container for the purpose of supplying heat to the transformer, and valves or doors being provided in the container. means being provided for causing the circulation of air through the container about the transformer when said doors are in open position, and other means being provided controlled by the pressure within the transformer for shutting thedoors and rendering the heating element active upon the presence of a predetermined pressure in the transformer during a rise in pressure therein from a minimum cycle pressure and for rendering the heating'element inactive and opening the doors upon a predetermined drop in pressure in the transformer from a maximum cycle pressure.

, The above being among the objects of the present invention the same consists in certain features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawings, and

then claimed, having the above and other ObJGCtS in view.

In the accompanying drawings which illustrate a suitable embodiment of the present invention, and in which like numerals refer to like parts throughout the several different views,

Fig. 1 is a partiallybroken side elevation of a refrigerating mechanism constructed in accordance with the present invention.

Fig. 2 is a view of the refrigerant transformer container taken on line 2-2 of Fig. 1, and showing the links which control the position of the valves or doors in the container and the valve controlling the flow of gas to the heating element.

F ig. 3 is an end view of a refrigerant transformer container as on line 33 of Fig. 1. Fig. 4- is an-enlarged side view of the mechanism for controlling the heating and cooling of the transformer.

- Fig. 5 is a sectional view through one of the refrigerant transformer tubes as on line 5-5 of Fig. 1.

Fig. 6 illustrates a typical pressure time curve for a refrigerating machine of the adsorption or absorption type using S0 as a. refrigerant.

Refrigerating machines of the absorption of adsorption t pe are so similar in their theory and met 0d of operation, as is well kno'wn to those skilled in the art, and as the present invention is equally applicable to either type of these refrigerators, reference will be hereinafter made onlyto the adsorber type of refrigerating mechanismsuch as 1s shown in connection with the present inven -tion, it being kept in mind that all reference to the adsorption type of machine refers equally well to the absorption type of machine except in the actual construction of the refrigerant transformer. In this type of machine difficulty has heretofore been experienced in controlling the application of heat to the transformer to boil ofi the refrigerant and thecooling of the same to effect an adsorption of the refrigerant from the evaporator so thatthe most satisfactory and economical operation of the'machine will result. The present invention employs the pressure in the transformer to control the period of heating and cooling the transformer, and inasmuch as the pressure in the transformer during the cooling period and during the increase of pressure therein is identical or almost identical with the pressure in the evaporator, which pressure is dependent upon the temperature of the evaporator, the application of heat to the transformer in the present invention is therefore dependent upon the temperature with in the evaporator.

The particular arrangement of the various units which, of course, may be varied to suit the desires or necessities of the particulardesigner, is shown in Fig. 1 as comprising a refrigerant transformer shown in the form of a plurality of coils of pipe 10, the interior of which may be filled with a broken mass of charcoal, silica gel or other adsorbing material 11, as indicated in Fig. 5, without materially interrupting the free flow of refrigerant through the same. The discharge end of the transformer 10 is connected to a condenser 12 which may be of any conventional construction and which discharges through the pipe 13' into a conventional receiver 14. A one-way valve or other check valve 15 is inserted in the pipe 13 and permits refrigerant from the condenser 12 to flow only in the direction of the receiver 14. The liquid refrigerant from the receiver 14 is conducted through a pipe 16 to an automatically controlled refrigerant feeding device such as the float type of valve 17 shown, which controls the flow of liquid refrigerant to the evaporator 18. The refrigerant which gasifies in the evaporator 18 is conducted through the pipe 19 back to the intake of the transformer 10, a check valve 20 being inserted in the pipe 19 to permit the flow of refrigerant only in the direction from the evaporator 18 to the transformer 10. The transformer 10 is enclosed in a container 21 the ends of which are provided with doors 22 secured to the vertically extending rotatable rods 23, two doors being provided in the present construction for each end of the container 21. The lower ends of the rods 23 are provided with levers 24 connected together by links such as 25 in such a manner that all doors are caused to open or close simultaneously with each other when a suitable actuating force is applied to any one of them. Within the right-hand end of the container 21 as viewed in'Fig. 1, and positioned between the doors 22 at that end 1s a gas plate or element 26 to which gas 'is conducted by means of a pipe 27 provided with a shut-off valve 28. A small pipe 29 bypasses gas around the valve 28 to the pilot light 30 which 15 adapted to burn continuously. The valve 28 is provided with an actuating lever 31 connected by a link 32 to one of the levers 24 whereby when the levers 24 are moved to swing the doors 22 to open position, the valve 28 will be closed, and when the lovers 24 are swung to move the doors 22 to closed position the valve will be opened.

A solenoid 33 provided with an armature (not shown) which is connected to one of the shafts 23 by means of the link 34 and lever 35 is provided for moving the doors 22 to closed position when the solenoid is properly energized, and a spring 36 connected to one of the lovers 24 is provided for moving the doors 22 to open position when the solenoid 33 is not energized. An electric motor 37 is positioned between the transformer 10 and condenser 12, it being provided with a fan 38 on one end of the shaft 39 for circulating air through the condenser 12. The other end of the shaft 39 projects into the left-hand end of the container 21 as viewed in Fig. 1, between the doors 22 at that end. and is provided with a fan 40 within the container 21.

The cycle of operation of a device of this type of course the same as in the conventional constructions.

Considering that the material 11 within the transformer 10 has adsorbed its capacity or near its capacity of refrigerant from the evaporator 18, heat is applied to the transformer 10 by means of the gas plate 26 which gasifies the refrigerant adsorbed by the material 11 and thereby causes a pressure to be built up within the transformer 10. This gasified refrigerant is prevented from returning to the evaporator 18 through the pipe 10 by reason of the check valve 20, and is therefore caused to flow into the condenser 12 where, because of the pressure. and the cooling effect on the same, it is liquefied and discharged through the pipe 13 and check valve 15 into the receiver 14 in liquid form from which it may be fed through the feed mechanism 17 to the evaporator. When the refrigerant has'been substantially all boiled out of the material 11, the gas plate 26 is turned off and doors 22 opened whereupon the fan 40 causes the air to flow through the container 21 and cool the transformer 10. This cooling of the transformer 10 again puts it in condition to adsorb the gasified refrigerant, or as it may be termed makes it hungry for refrigerant. This causes a suction to be built up within the transformer 10 which draws the gasified refrigerant into the same from the evaporator 18 and this continues until the material 11 has again adsorbed its capaoity or near its capacity of refrigerant. I prefer to allow the motor 37 to be operated continuously, the fan 40 serving to circulate the heated air within the container 21 when the doors 22 are in closed position, although it will be readily understood that it may, if desired, be connected with the solenoid circuit as will hereinafter be described so that it is operated only when thedoors 22 are opened.

The commercial difficulty with this type of refrigerating device has heretofore been that no commercially practicable means have been provided whereby the transformer is heated upon the presence of a predetermined temperature within the evaporator 18, and is cooled when only a predetermined percentage of refrigerant remains in the material 11 during the heating period. The mechanism for controlling the periods of heating and cooling during each cycle of operation of the mechanism and which forms the subject matter of my application for Letters Patent of the United States for improvements in control mechanism, filed on evendate herewith, is shown in the large view in Fig. 4 and depends for its action onthe variation 6f pressure within the mechanism.

Fig. 6 which illustrates a typical curve of the pressure variations within a device of this type plotted against elapsed time when S0 is used as a refrigerant, shows curve A as the pressure within the transformer and curve B as the pressure in the evaporator.

will be noted that the pressure within the transformer at zero minutes on the graph, it

will be noted that the pressure within the same immediately mounts to a maximum and then begins to fall off as the refrigerant is driven from the adsorbing material. It will be noted that the curve A in dropping from the maximum value at first has a tendency to drop relatively fast and then tends to gradually straighten out. If heat were continued to be supplied to the transformer for an appreciable lengtlfof time after the curve A begins to thus flatten out, uneconomical operation would result because of the relatively small further amount of refrigerant which would thereby be driven out of the adsorbing material. It is therefore desirable, from an economical standpoint, to discontinue the heating immediately or shortly after the curve A thus begins to flatten out. When heat is thus discontinued and the trans,- former is cooled, the pressure Within the transformer immediately drops as indicated, the rapidity of the drop being dependent to a great extent upon the specific heat of the tubing 10, material 11 and the container 21. The curve A will therefore drop until it has reached a minimum value at which time the rate at which the refrigerant is being dis-.

charged from the evaporator will exceed the now decreased ability of the material 11 to adsorb the same with the result that the pressure will gradually increase, resulting in an increase in the temperature within the evaporator until such temperature is reached that it is again desirable toagain boil off the refrigerant in the transformer. During the boiling off period, inasmuch as the pressure within the transformer is not communicated 'to the evaporator, and as the transformer is not capable of adsorbing refrigerant from the evaporator during this period, the temperature and pressure within the evaporator will continue to rise as indicated by the curve B, but when the transformer is cooled, the pressure within the evaporator, except for such resistance as maybe setup by the check valve 20, will be identical with the pressure within the transformer so that during substantially all of the absorbing period the curves A andB will coincide. The maximum pressure during the boiling off period in the transformer may vary for any given refrigerant, and in case of SO as much as 15 to 20 pounds above or below the maximum value indicated, and may vary one or two pounds above-or below the minimum value indicated. Other refrigerants will, of course, have curves of the same general characteristics as those shown for S0 gas except for the-difference in maximum and possibly the minimum pressures indicated.

The control mechanism employed in connection with the present invention is constructed so as to utilize a predetermined-drop i in pressure from each maximum cycle pressure for rendering the heating element or the transformer inactive, and utilizes a predetermined increase of pressure from a predetermined low pressure value during each increase in pressure within the transformer from a minimum cycle pressure therein for rendering the'heating element active and the coolingmeans inactive. This mechanism, as indicated in Fig. 4, comprises a support 41 at one end of which is mounted a pressure responsive element which is shown in the form of a metal bellows 42. The interior of the bellows is sealed against the atmosphere and is connected by the tube 43 to the transformer 10 by means of a connection such as 44 as illustrated in Fig. 1. At one side of the bellows 42 is a standard 45 rigidly secured to the support 41 by screws 46. A lever or arm member 47 is pivotally connected at one end by the pin 48 to the upper end of the standard 45 and extends across the top of the bellows 42 to which it is pivotally connected by the pin 49 and arm 50to the top of the bellows. The opposite end of the arm 47 extends toward the opposite end of the support 41 and is pivotally connected by the pin 51 to one end of the short link 52. The opposite end of the link 52 is supported from the support :41 through the pins 53 and 54, the vertically extending link 55 and bracket 56. An upwardly extending arm 57 is secured to the link 52 41 extends upwardly to a point adjacent the upper end of the arm 36 where it is provided with a pair of spaced adjustable screws 59 and 60 positioned in the path of movement of the arm 57 and which serve as limited stops for the pivotal movement of the arm 57. A mercury switch 61 of conventional construction is secured to the arm 57 in such a manner. that when the arm 57 is at the right-hand extremity of its movable position, as viewed in Fig. 4, the drop of mercury 62 therein will have flown to the right-hand end of the switch 61 so as to close the circuit between the terminals 63 and 64. and when the arm 57 is at the left-hand extremity of its movable position, the mercury 62 will have flown to the left-hand end of the switch so as to break the circuit through the terminals 63 and 64. It will be apparent that the bellows 42 being in communication with the interior of the transformer 10 will tend to expand when pressure is built up within the transformer and will move the arm 47 upwardly about the pin 48, and when the pressure within the transformer 10 is decreased the bellows 42 will tend to contract and move the arm 4 downwardly about the pin 48. I

Considering the mechanism illustrated in Fig. 4 as having a pressure within the bellows 42 equal to a maximum cycle pressure with the transformer 10, it will be noted that as the pressure begins to drop and the arm 47 moves downwardly in accordance therewith. the link 52 will be caused to move downwardly at a relatively greater angular velocity than the arm 47 because of its relatively shorter length. As soon as the link. 52 begins to move downwardly it will carry the arm 57 with it. thus causing the mercury 62 to run to the opposite end of the switch 61 and break the circuit through the terminals 63 and 64. 'It will also be apparent that a relatively small movement of the arm 47 will be sufficient to move the arm 57 into contact with the screw 59. thereby preventing further movement of the arm 57, although the arm 57 and link 52 may continue to move downwardly because of the frictional connection between the arm 57 and link 52. The arm 47 and link 52 will continue to move downwardly until the screw 65 carried'by the arm 47 contacts with the stop 66 on the base 41 which will be at a time when the pressure within the transformer has approached its minimum value. Further dropping of the pressure in the transformerwill thus be ineffective to move the arm 47 and link 52.

'As the pressure within the transformer again begins to build up from the minimum value,

'it will reach a point where it begins to lift vent further movement of the arm 57 but will not prevent further movement of the arm 47 and link 52, as has been previously described.

It will be noted that it is only necessary for an initial movement of the arm 47 in either direction to actuate the switch 61. In order to increase the amount of drop in pressure in the transformer which will'be necessary to render the heating element inactive and thereby be assured of a predetermined amount of refrigerant being boiled out of the material 11, an adjustable spring 67 is provided on the support 68 in the path of movement of the arm 47 so as to oppose upward movement of the arm 47 after it has moved upwardly a predetermined amount. It is also preferable to provide means for urging the lever 47 downwardly through the entire range of its movement in order to overcome any possible set in the metal of the bellows 42 and to take up any play that may develop in the connections. This means may take the form of a vertically slidable pin 69 carried by the bracket 68 and constantly urged downwardly against the arm 47 by means of the relatively light coil spring 70. The terminals 63 and 64 are connected through a suitable source of electrical energy to the solenoids 33 so that upon the presence of a predetermined pressure in the transformer during a rise in pressure therein from a minimum cycle pressure, the solenoid will be energized and will shut the doors 22 and turn on the gas to the'plate 26 whereupon the transformer will be heated; and upon a pre determined drop in pressure in the transformer from a maximum cycle pressure, the circuit to the solenoid 33 will be broken and the spring 36 will shut off the gas to the plate 26 and will open the doors 22 to allow air to be circulated through the container 21 and cool the transformer 10.

It will be apparent from the foregoing that instead of a single control device, as shown and described, actuated both by a rise in pressure and a fall in pressure within the transformer, two separate control devices may be employed, one of which may be connected either to the transformer or the condenser and' be actuated upon a decrease in pressure therein to discontinue the heating of the transformer and to begin the'cooling ofthe same,- and the other of which may be connected to either the transformer or the evaporator and be actuated by an increase in pressure therein to discontinue the cooling and render the heating of the transformer 10 active,but for simplicity in construction and economy in production it is preferable to combine such control means as shown.

It will also be apparent that various other modifications of the construction shown may be readily made by those skilled in the art to suit their particular problems or fancies in said without departing from the broader aspects of the invention involved, and formal changes may be made in the specific embodiment of the invention described Without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

1. In a refrigerating system of. the class described, a refrigerant transformer, a condenser and an evaporator connected there With, heat supplying means for said transformer, and means for rendering said heat supplying means inactive actuated by a pre determined drop in pressure in said system from a maximum cycle pressure therein.

2. In a refrigerating system of the type described, arefrigerant transformer, an evaporator and-condenser connected therewith, heat supplying means for said transformer, and means for rendering the heat supplying means active actuated by the presence of a predetermined increase in pressure in from a minimum cycle pressure.

3. In a refrigerating system of the type described, a refrigerant transformer, an evaporator and condenser connected therewith, heat supplying means for saidtransformer, means for rendering the heat supplying means active actuated by the presence of a predetermined increase in pressure in said system during a rise of pressure therein from a minimum cycle pressure, and means for rendering said heat supplying means inactive actuated by a predetermined drop in pressure in said system from a maximum cycle pressure therein.

4. In a device of the type described, a refrigerant transformer, a condenser and an evaporator connected therewith, means for supplying heat to said transformer, and means for rendering the heat supplying means inactive actuated by a predetermined drop in pressure from a maximum cycle pressure in said transformer.

5. In a device-of the class described, a

refrigerant transformer, a condenser and evaporator connected therewith, heat supplying means for said transformer, and means for rendering the heat supplying means active actuated by a predetermined increase in pressure in said transformer during a rise of pressure therein from a minimum cycle pressure.

6. In a device of the class described, a refrigerant transformer,- a condenser; and evaporator connected .therewlth, heat supplying means for said transformer, means for rendering the heat supplylng means active actuated by a predetermined increase in pressure in said transformer during a rise of pressure therein from. a minimum cycle pressure, and means for rendermg the heat supplying means inactive actuated by a presystem during a rise of pressure theredetermined drop in pressure from a maximum cycle pressure in said transformer.

7. In a refrigerating mechanism of the class described, comprising a refrigerant circulating system including a refrigerant transformer and high and low pressure sides, means for supplying heat to said transformer, and means for renderin said heat supplying means inactive actuate by a predetermined drop in pressure in said high side from a maximum cycle pressure therem.

8. In a refrigerating mechanism of the class described, comprising a refrigerant circulating system including a refrigerant transformer and high and low pressure sides, means for supplying heat to said transformer, and means for renderin said heat suppl ing means active actuated %y the presence 0 a predetermined increase in pressure in said low side during a rise in pressure therein from a minimum cycle pressure.

9. In a refrigerating mechanism ,of the class described, comprising a refrigerant cir-. culating system including a refrigerant transformer and high and low pressure sides, means for supplying heat to 'said transformer, means for rendering said heat supplying means active actuated by the presence of a predetermined increase in pressure in said low side during a rise in pressure therein from a minimum cycle pressure, and means for rendering said heat supplying means inactive actuated by a predetermined drop in pressure in said high side from a maximum cycle pressure therein.

10. In a device of the class described, a refrigerant transformer, heat supplying means for said transformer, cooling means for said transformer, and means for rendering said heating means inactive and said cooling means active actuated by a predetermined drop in pressure in said transformer from a maximum cycle pressure therein.

11. In a device of the type described, a refrigerant transformer, heat supplying means for said transformer, coolin means for said transformer, and means for rendering said cooling means inactive and said heat supplying means active actuated by the presence of a predetermined increase in pressure in said transformer during a rise of pressure therein from a minimum cycle pressure.

12. In a device of the type described, a refrigerant transformer, heat supplying means for said transformer, cooling means for said transformer, means for rendering said cooling means inactive and said heat supplying means active actuated by the presence of a predetermined increase in pressurein said transformer during a rise of pressure therein from a minimum cycle pressure, and means for rendering said heating means inactive and said-cooling means active actuated by a predetermined drop in pressure in said transformer from a maximum cycle pressure therein.

13. In a device of the class described, a refrigerant transformer, a gas plate in proximity thereto, a valve for controlling the flow of gas to said plate, and means actuated by a predetermined drop in pressure from a maximum cycle pressure in said transformer for closing said valve.

14. In a device of the class described, a refrigerant transformer, an evaporator connected thereto, a gas plate in proximity to said transformer, a valve for controlling the flow of gas to said plate, and means actuated by a predetermined increase in pressure attained in said evaporator during a rise in pressure therein from a minimum cycle pressure. for opening said valve.

15. In a device of the class described, a refrigerant transformer, an evaporator connected thereto, a gas plate in proximity to said transformer, a valve for controlling the flow of gas to said plate, means actuated by a predetermined increase in pressure attained in said evaporator during a rise in pressure therein from a minimum cycle pressure for opening said valve, and means actuated by a predetermined drop in pressure from a maximum cycle pressure in said transformer for closing said valve.

16. In a device of the type described, a refrigerant transformer, heat supplying means therefor, means for cooling said transformer including valvular means, and pressure actuated means connected to said transformer operable to render said heat supplying means active and shut said valvular means actuated by the attainment of a predetermined increase in pressure in said transformer during a rise in pressure therein from a minimum cycle pressure and to render said heat supplying means inactive and open said valvular means actuated by a predetermined drop in pressure in said transformer from a maximum cycle pressure therein.

17. In combination, a container, a refrigerant circulatory duct and a heating means for said duct in said container, openings in said container, valvular means co-operating with certain of said openings for opening or closing the same, and means operated by reversals of the pressure in predetermined amounts .in said duct for simultaneously rendering said heating means operative and closing said valvular means, and for simultaneously rendering said heating means inoperative and opening said valvular means.

18. In a device of the class described, a container, a refrigerant duct in said container, openings in said container, valvular means for opening or closing certain of said container openings to the passage of a heat transferring medium, and a constantly operated fan for causing a flow of said medium valvular means are in closed osition.

CHARLES THOMAS. 

